The field of the invention is devices for constructing farm or highway fencing including woven wire, chain link and/or barbed wire attached to posts spaced as may be required. More particularly the field is devices for unwinding fencing wire rolls and tensioning said wire properly for attachment to the posts.
State of the Art usually consists of unrolling fencing wire on the ground along a fence line of preset posts. The wire is then attached to a properly braced fence post and a limited length is stretched along the other posts and attached to said posts. The fence is manually stretched by clamping the free end of the wire and pulling on the clamp by means of a vehicle, block and tackle, come-a-long or some type of lever device. There are a small number of devices that spool the wire along the post line in a vertical configuration for attachment to the preset fence posts. Most of these require a separate operation to stretch the wire properly before attachment to the posts. U.S. Pat. No. 2,914,270 discloses a vertically mounted woven wire dispenser that carries a single roll of wire. It is used to dispense wire vertically but uses a manually operated hydraulic valve to clamp the wire and stretches the wire by moving the carrying vehicle in a separate operation. This method can result in distorted wire and is time consuming. U.S. Pat. No. 4,854,521 discloses a fence wire dispensing and stretching device that applies pressure to the top and bottom of a roll of wire that would appear to lose some of its frictional effect upon the roll of wire when nearing the end of the roll or possibly distort the roll of wire. There are indications that this device is lacking in adequate positive tensioning power. This device also requires a separate and expensive hydraulic cylinder to put enough pressure on the wire in order to hold the end of the roll from passing through the guide rollers before the next roll of wire is spliced on to continue the spooling operation. Other disadvantages are the expense of constructing the said device and that it does lose it tensioning of the wire when the vehicle is stopped. In addition to the previous disadvantages it has a large number of moving parts and the wear on the compression plates at the top and bottom of the wire rolls will wear excessively. U.S. Pat. No. 4,930,718 discloses a device for dispensing woven wire but does not provide for the stretching of the wire on the posts. U.S. Pat. No. 5,632,470 discloses a device to dispense barbed wire and using hydraulic pistons on individual stands of wire. This would be very time consuming when building long fences. U.S. Pat. No. 3,104,863 discloses a device to spool and stretch wire along fence posts. However the stretching of the wire is a separate operation which requires the stopping of the spooling operation. This is more time consuming to operate and embodies expensive parts to construct. U.S. Pat. No. 3,722,861 discloses a very complicated and expensive to build device that uses hydraulic power on a brake drum to tension the fencing wire as it is dispensed. This device could be difficult to use on varied terrain and depends on metal forks to hold the wire that may that may cause distortion in the wire fabric. It would also require the on spooling of wire to reload the spooling device and carries only the one roll.